Cracks in the Ice
by dragonwriter24cmf
Summary: Mycroft has a condition that Sherlock was never supposed to know about. When he's unexpectedly rendered incapacitated in Sherlock's flat, the younger Holmes has choices to make. How will he handle a brother who needs his care and support, instead of the other way around?


**Cracks in the Ice**

Neither of them were expecting it, when it happened.

They'd taken to meeting once every week after Sherlock's near-exile, following the Magnusson case. It was a compromise of sorts. In Mycroft's words, "The most viable alternative to implanting you with a subcutaneous transponder or five, or locking you in a small, highly fortified property to avoid subjecting myself to further stress."

In Sherlock's words, "Less tedious than having to avoid your imbecilic henchman, and less boring than having to deal with your surveillance."

Which led to the meetings. Which usually involved tea (provided by Mrs. Hudson, and paid for by Mycroft), a game of chess or something else intellectual, and a discussion about the various happenings in each others lives. Sherlock's cases, any news that Mycroft felt necessary to impart, particularly in the interest of keeping his wayward younger brother out of trouble. Such as the status of the Watsons (relatively safe, no more blackmailing idiots on the horizon) the state of the nation (who knew where another case to keep Sherlock occupied might be), and other matters of interest. Mycroft had little interest in chemistry and experimentation, but he'd listen politely if it meant Sherlock would stay put. Sherlock found politics boring, but he would listen, if only to retain those tidbits that might be useful for future reference.

They made do, and the result was a slightly less strained relationship, and a mending of the wounds caused by Moriarty and Magnusson. John would even have called the relationship amiable, having learned the difference between the two brothers fighting and the two brothers simply sniping at the only other person they knew who could both tolerate it and appreciate the subtleties of Holmesian humor.

But even as far as they'd come, neither of them were expecting what happened, on a blustery September day.

The weather had been rougher than usual, weather systems shifting between high and low pressure fronts with annoying frequency. Both brothers had been a bit shorter in their tempers during the meeting, their sniping a bit more pointed, and it resulted in an unspoken agreement to end the encounter early, before tempers and words got too far out of hand.

They said their farewells, Sherlock rose to show Mycroft to the door (a habit developed after Mycroft deliberately bugged his flat three times to encourage it), and Mycroft followed in his usual stately, stalking gait.

He got all of two steps before he stopped abruptly, jerking as if he'd walked into something, blinking hard.

That was all the warning Sherlock had before Mycroft collapsed, crumpling to the floor as though his knees had both been broken at once, dropping with a hiss of in-drawn breath that, for Mycroft, was synonymous with a cry of pain.

Sherlock was only a second behind him, though his drop was a controlled crouch. "Mycroft? Mycroft?"

The words, spoken at normal volume (not very loud at that), resulted in another hiss of pain, this one much more defined, as well as an aborted movement that looked as though Mycroft was attempting to cover his ears. He was curled partially on his side, and as Sherlock moved to get a better look at his brother's face, he realized that the hand trapped beneath him had been moved to cover Mycroft's eyes.

 _Sudden onset pain. Light apparently hurts, judging by the position of the one hand. Reaction indicates noise is also painful. Movement stopped, abruptly. Conclusion, pain caused and exacerbated by external stimuli. Personal experience indicates most likely cause is a headache of some sort._

He'd had enough hangovers and drug-induced headaches to know the signs, but he'd never heard of Mycroft having one. Besides, there had been no drugs or alcohol involved. It was one of Mycroft's rules. If he wanted to retain his independence, he had to retain his avoidance of addictive substances. In truth, his brother's visits and his own work, to say nothing of John and Mary's frequent presence, made the stipulation an easy one.

None of that mattered. Acting on the data he had and his own tentative hypothesis, Sherlock moved to draw the shades over the windows. Then he turned off all lights except for the low powered one by his favorite thinking chair, the one John had insisted he keep to prevent other people having heart attacks when they came in and he was sitting quietly. He'd agreed, on the provision that it was made clear that he wasn't to be disturbed if the light was on and he was in the chair.

That done, he returned to his brother's side. Mycroft hadn't moved from the floor, which was alarming in and of itself. Under normal circumstances, his brother would despise lying on a floor. Especially in a suit.

In another time and place, Sherlock might have teased his brother. But mocking Mycroft was only worth the effort when he could return fire. And for all his brother's sins, Mycroft had never insulted him during his own injury and recovery periods. Scolded, yes. Questioned, certainly, especially when it involved drugs. Lightly mocked, only when he was recovered enough to respond in kind, and had given verbal and physical indication of that fact.

But that did leave the question of what he could do. Speaking hadn't worked well earlier, and he wasn't at all sure about moving his brother. Not with the way Mycroft had stopped, then collapsed.

 _Spoken word produces an adverse reaction. Therefore, unspoken communication is required. Visual communication equally impaired. Conclusion: Tactile communication provides optimum results. But in what form? Something requiring a minimum of focus, easily understood and comprehended...ah._

Mycroft still had one hand free. Sherlock wrapped tentative fingers around his wrist, measuring the pulse at the same time he caught Mycroft's attention. Mycroft twitched at the touch, but made no other move. He offered no resistance as Sherlock turned his hand palm up and tapped out a quick sequence of dots and dashes.

 **'Talk this?'** Mycroft could harass him for the grammatical atrocity of it later.

After a moment, Mycroft's finger moved and tapped out a weak response. **'Yes.'**

 **'Needs?'**

 **'Quiet. Dark. Med.'**

 **'Where Med?'**

 **'PA'**

Sherlock huffed out an exasperated and soundless breath. Of course Mycroft would leave his medicine with his Personal Assistant. His brother would never risk bringing anything that might be a temptation into the flat, not even with his promise. Too worried that he might decide to try some form of experiment or another.

 **'Number?'** Mycroft insisted that he be Sherlock's contact with his office, regardless of inconvenience.

Mycroft's response came in the form of slow numbers traced on his hand, rather than Morse Code. Sherlock entered the numbers into his own phone, then typed up a quick text message.

'Sherlock here. Mycroft is ill. Requires medicine for headache. Bring at once, along with any other known required items.'

He'd just finished the message when Mycroft moved again, tapping out a word.

 _'Sunburst. Not a response to a question. Current sensitivity can most likely detect sound of texting. Conclusion: Sunburst is a pre-established code for current condition.'_ He typed it in and sent his message.

Moments later, his blackberry buzzed with a reply.

'I will arrive in 5 minutes. Meet me outside the door.'

He sent a confirmation, then took Mycroft's hand again.

 **'PA OHW. 5 min.'**

It took longer than it should have for Mycroft to squeeze his hand in confirmation. Once he had it, Sherlock rose to his feet and moved toward the door, stepping as lightly as he could. Fortunately, he'd had plenty of practice in silent movement.

Mycroft's personal assistant was as good as her word. He'd not been standing outside the door to 221B for longer than 2 minutes when she arrived, carrying what looked like a meal bag.

She tilted her head in greeting, but didn't say anything. Instead, she opened the bag and pulled out a bottle of pills, with a note attached. 'Two pills with water. Two more in four hours if no improvement. If no recovery in eight, call for medical assistance.'

He nodded his compliance. She replaced the pills and took out a bottle of water. 'For the pills.'

Of course. Running water would grate on Mycroft's sensitive hearing. He nodded again.

She put it back, then produced a sleep-aid mask. The purpose of that was obvious, as were the earplugs she produced with it.

The last item was a list of instructions.

'Medicate'

'Move somewhere comfortable, dark and quiet.'

'Remove shoes and tie. If conscious, remove jacket and waistcoat. If not, unbutton and loosen.'

'Let sleep when possible.'

'Supply water and meds as needed, and any other necessities. Do not disturb otherwise.'

'Do not attempt food until fully awake and pain-free.'

'Avoid noisome odors. May cause nausea or increased severity of condition.'

'Do not allow out of room until subject has eaten and remained conscious and capable of normal communication for minimum of two hours.'

'Avoid cranial impact or high stress for minimum of four hours to reduce likelihood of repeat episode.'

The last would be the most troublesome, and Mycroft was likely to find the entire thing stressful, but the list was manageable. He nodded again.

The personal assistant smiled, then tapped out a quick message on her phone, which popped up on his. 'Text me updates in the morning, and if you require anything. I have the number for his physician if needed.'

He'd probably call John if he needed a doctor, or Molly Hooper. Nevertheless, he nodded again. She tilted her head in recognition, then turned and vanished back down the stairs, leaving him with Mycroft.

He rather wished she'd stayed, but no doubt she had work to do, managing the rearrangement of affairs for his brother's so-called minor government position. He looked at the sack in his hands, then turned and let himself into 221B as noiselessly as he could manage.

Mycroft had shifted position a little in his absence, but he hadn't even gotten off the floor and, judging from his brother's face, the movement had cost him. Mycroft's lips were compressed into a hard, thin line, face drawn and pale with pain even in the poor lighting. One hand was still clamped over his eyes, the other clenched at his side.

An unenviable position, and one Sherlock found himself sympathizing with.

All right then. The first step was medication. Sherlock crouched beside his brother and touched Mycroft's clenched hand to get his attention. Mycroft flinched, though the movement seemed one of surprise rather than pain (no sounds, no tensing of the shoulders), though Mycroft's jaw clenched a moment later as the movement exacerbated his condition. Still, he opened his hand, palm up, to Sherlock.

Rather than waste time with words, Sherlock dumped two pills into the proffered palm, catching Mycroft's wrist when he realized that Mycroft's hand was shaking (pain and stress, no doubt). He guided Mycroft's hand to help him tip the pills into his mouth, uncapped the water bottled and tipped a little liquid in after, and Mycroft swallowed.

Sherlock consulted the next item on the list. Move Mycroft somewhere quiet and dark and comfortable.

John's old room was immediately discarded as a choice. Not only would the stairs prove a hideous ordeal for both of them, but John had never installed shades in his window. He liked sunlight. Also, John's idea of comfort when he'd been living with Sherlock had been very much of the bachelor/soldier variety. Not ideal for Mycroft.

To say nothing of his bed, which was meant to accommodate a man of shorter-to-average height who was used to military bunks. Sherlock didn't particularly like sleep, or engage in it often, but when he did, he made sure to be comfortable. And unlike John, he did like the dark, as it provided fewer distractions.

So, his room it would be then. He'd probably sleep on the sofa, if he bothered at all.

Which left the question of getting Mycroft from his sitting room floor to his bed. The how was fairly straightforward. He was fairly certain he possessed the required physical strength to shift his brother, particularly as Mycroft still seemed at least partially aware. The question was whether Mycroft's current condition could tolerate the movement, and what the consequences might be if not.

He finally abandoned the analysis in his head as a bad job, not having enough data to make a proper determination, and reclaimed Mycroft's hand to tap out a simple message.

 **'Move? Bed.'**

Mycroft shuddered. Then hissed in pain. Then slowly tapped out a very reluctant answer. **'Yes.'**

Sherlock nodded to himself. He considered the dynamics of the maneuver, then removed the sleep mask and earplugs from the bag he'd been handed. He tapped the hand over Mycroft's eyes with the mask. After a very long moment, Mycroft moved his hand, and Sherlock was able to slip the mask around his brother's head, blocking the light.

With careful touches, he conveyed his intentions to shift Mycroft's head, then tilted it so that both ears were visible. Then he tapped the earplugs into place, using the same care that he used for his more volatile experiments, or working a crime scene that Lestrade insisted he not contaminate.

Even with his efforts, Mycroft hissed in pain, hands clenching and twisting in the carpet. Still, he was rewarded for the trouble with a slight relaxation of his brother's shoulders when he was done, and judged the endeavor to have been worth it.

That done, he took Mycroft's hand and tapped out a quick message.

 **'Ready?'**

 **'No. Yes.'** Mycroft's shoulders tensed as he tapped out the faltering reply.

Sherlock suspected his brother was more than ready to get off the floor, and that his reluctance involved the possible consequences of movement. He considered waiting for the medicine to take effect, but the instructions he'd been given indicated that it might be hours before Mycroft was capable of moving without pain. That was unacceptable.

 **'Moving now.'**

Once Mycroft squeezed his hand in acknowledgment, Sherlock worked both arms under his brother's shoulders and pulled him into a sitting position. Mycroft worked with him as best he could, but there was no disguising that movement was agony for his brother. Low, half-heard moans wrenched from Mycroft's throat, and once sitting he dry-heaved, evidently suffering from pain-induced nausea on top of everything else. That or dizziness caused by aural disruption.

Either way, Sherlock was rather glad now that he'd been feeling inhospitable, and Mrs. Hudson had been out shopping. Particularly if, as the note indicated, Mycroft might also be sensitive to certain odors.

Getting Mycroft to his feet proved a similar ordeal, and once upright, Sherlock found himself supporting most of his brother's weight. Fortunately, Mycroft's latest diet had been going well, and said weight was not much greater than his own. It was bearable.

The low, shuddering breaths, suspiciously like groans or cries of pain, were much less so. He'd never heard Mycroft make such noises.

The best thing to do would be to get Mycroft situated, so he could stop moving, and hopefully the pain would subside. With that in mind, Sherlock calculated the fastest and smoothest route from where they stood to his bed, and began moving, taking small, careful steps and drawing Mycroft along with him. The elder Holmes could barely move, and every step seemed to induce what, in any other person he might have called whimpers.

 _'How does his PA deal with this? Evidence suggests she must have, but her size is not conducive to transport, and this is an astonishingly awkward situation.'_

He set that thought aside for later contemplation, guiding Mycroft into his bedroom.

 _'Instructions say to remove coat, waistcoat, tie and shoes. Loosen and unbutton shirt collar. Mycroft is currently only semi-responsive. It will have to be done quickly. Before he is prone, in the case of his upper garments.'_

He stopped Mycroft beside his bed, then freed one hand and began to undo the buttons of Mycroft's coat and waistcoat. Mycroft made no move to stop him, even as he tugged the tie loose from it's well-snugged position at Mycroft's throat. Either the medicine was finally working and reducing Mycroft's consciousness to non-existence, or Mycroft's pain had increased to the point of insensibility.

Sherlock found himself preferring to think of the first outcome.

He got the tie loose enough to slip it easily over Mycroft's head, even without his brother doing anything help. That done, he eased the coat and waistcoat down from Mycroft's shoulders, calculating the best way to manage.

 _'Mycroft is barely standing. Released, he will most likely fall. Forward momentum will land him on the bed. Holding coat and waistcoat at a specific angle will facilitate their removal. However, it will result in difficulties controlling Mycroft's descent. Calculated risk is acceptable, but best to be aware of potential consequences. Highest likely consequence, greater pain, possibility of dry heaving or even outright vomiting.'_

The other option was to try and manage Mycroft's jacket while holding him up. If Mycroft had been any steadier, or if he'd had anyone to help him, then he might have attempted it. But he wasn't sure of whether or not he could manage on his own.

He loosened the jacket as much as possible, then very carefully tipped Mycroft toward the bed. Mycroft toppled without resistance, crumpling into the bed with the same haphazard abandon he'd collapsed in the living room. It was disconcerting, as was the strangled noise Mycroft made when he hit the mattress. It shouldn't have hurt, Sherlock had toppled into that mattress often enough to know how soft it was. He'd been injured often enough to know the mattress was relatively easy on wounds as well. And headaches.

The way Mycroft winced and hissed out a painful groan, his headache must be excruciating indeed. Given that it had been several minutes since he'd given his brother the medicine, that was not encouraging. Mycroft's metabolism was nowhere near as fast as his own, but he'd still hoped for results sooner.

Still, he had succeeded in his objective of getting Mycroft onto the bed, mostly, and had managed to divest him of jacket, tie and waistcoat. Hopefully, the bed was soft enough that it did not violate the 'avoid cranial impact' section of the list Mycroft's assistant had given him.

He crouched and removed Mycroft's shoes, then levered his brother's legs up onto the mattress. Mycroft made another sound, a feeble protest at the manhandling.

That done, Sherlock paused. There were still three hours until he could determine whether Mycroft might need a second dose of medication. He consulted the list in his mind again.

'Let sleep when possible. Provide water and meds as needed. Do not disturb otherwise.'

He extracted the water bottle from the bag and set it on the bed, next to one of Mycroft's limp hands. Mycroft made no indication that he'd noticed, so Sherlock turned and padded out of the room with silent steps, closing the door as far as he dared. He didn't shut it all the way, knowing from experience that it made a rather loud 'snick' when it shut.

That done, he retreated to the living room once again and, after a moment, pulled out his phone to text John.

'Mycroft visiting. Collapsed with what appears to be a headache. Sensitive to light, sound, and movement, to the point of nausea and visible discomfort. I have contacted his assistant and applied the medicine she has given me, but I am open to further suggestions by a medical expert.'

Moments later, his blackberry buzzed in reply. 'Sounds a bit like a migraine. Have you moved him some place dark and quiet?'

'He is in my room, and most of the lights in the flat have been extinguished.'

'Well, that's about all you can do. Migraines are a nasty business. If you've given him medicine already, there's nothing to do but wait it out, I'm afraid.'

'Three hours remain until a second dosage is administered. Seven until I am advised to contact medical personnel. Will you be available if I have need of you?' He wasn't generally inclined to ask, but this wasn't a case that he might need help or a sounding board for. And John and Mycroft had never been on the best of terms.

Besides, he'd been trying to be somewhat considerate since John's marriage. He was more likely to receive things he requested from the doctor if he made the occasional attempt at courtesy. To say nothing of avoiding Mary's temper. It was unwise to provoke a former assassin, let alone one who was hormonally compromised.

'Should be. You know I usually am, if it's you.'

'For cases. This is not a case.'

'Yeah, well, medical stuff too. The only reason I'm not more available for that is because you never ask, you wanker.' It was almost inspiring how John could convey emotion, even via text message.

'Duly noted. I shall text if I have need of your assistance.'

'Right. Have fun with your brother.'

He thought that might be sarcasm. Though it did bring to mind some experiments and such that he'd had in mind to try, regarding Mycroft…

Only, Mycroft had a knack for getting payback. And his PA was likely just as devious. And John would probably disapprove.

Resolved to wait at least until Mycroft was recovering, he turned his attention towards the task of looking up migraines. He'd had some experience with this sort of headache himself, but he'd chalked it up to mental strain, the side effect of a mind that almost never shut off, or a side effect of some concoction he'd ingested or been dosed with. Something powerful enough to fell Mycroft, however, was worth investigating.

Two and a half hours of investigating yielded equal parts frustration and enlightenment, and no small amount of concern.

The frustration came from the fact that little was known about the actual causes of migraines. There were several triggers (stress being a primary one, which explained a lot), but no known definitive causes. The primary theory he discovered was some sort of neurological malfunction.

The enlightenment came in the lists of triggers, symptoms, and additional suggestions for mitigation. The primary suggestions were medications, and removal of irritants or stressors. He knew that, but the idea of a warm towel, or particular soothing scents (lavender and vanilla and eucalyptus, odd combination) were new. Doubtless, Mycroft had an aversion to both solutions.

It was amusing to picture his brother turning up at a government meeting smelling like lavender and vanilla instead of the subtle colognes he usually favored. It would probably spark a Parliament-wide speculation on which gender Mycroft preferred in his bed.

The concern came from the lists of possible symptoms. Blindness. Seizures. Unconsciousness, from pain alone. Violent nausea. An inability to tolerate any sort of physical stimulus, including contact. And pain that could last for days with varying intensity. Pain varying from a dull throb, to unbearable agony that completely crippled a person.

Even more concerning, the lack of concrete answers regarding the cause meant that effective treatment was difficult, nearly impossible, and often dealt with on a case by case basis, varying from headache to headache even with one individual. Nor were the headaches themselves predictable, which was how Mycroft had been caught unawares leaving Sherlock's flat.

Mycroft liked things ordered, reasonably predictable. Controllable. Something like this would be a source of supreme frustration for him. Under other circumstances, Sherlock would have applauded anything that inject a little chaos into his brother's life. But this…

He liked causing Mycroft headaches of a purely mental and frustration-based variety. Not watching his brother succumb to debilitating pain for no reason he could discern. Besides, if the theories of a neurological based disorder as the cause were true, then migraines might effect him as well. He didn't enjoy the idea of collapsing in the middle of a case the way Mycroft had today.

John would help him through it, but Mrs. Hudson would fuss, and the denizens of Scotland Yard would be insufferable, discovering that he could be toppled like a mere mortal. Lestrade might be reasonable, but Donovan would be intolerable.

A glance at his phone revealed that the four hours dictated between medications had almost elapsed. Sherlock rose and padded back to the room, pushing it open with careful pressure to avoid creaking hinges.

Mycroft hadn't moved. He still lay in a limp sprawl where Sherlock had left him, mask on, earplugs firmly in place. That was...not encouraging. From the looks of it, he hadn't even drunk the water Sherlock had placed beside him.

Sherlock made his way over, studying his brother.

 _'Very little tension, but very little relaxation. Position would not be comfortable with Mycroft's physical state, but he has not moved. Conclusion, he either lost consciousness before the pain dissipated enough for him to move, or he is still in pain and incapable of movement. Breathing is short, leads credence to the later theory.'_

That was, as John would put it, a bit not good.

He reached out and touched Mycroft's nearer hand. Mycroft twitched, then flinched deeper into the blankets, confirming Sherlock's theory. His brother was in pain still.

He tapped out a slow code on the back of his brother's hand. **'More Med?'**

 **'Yes.'**

Sherlock poured two more capsules into his palm, then paused. There was the issue of how to get Mycroft to take them.

He stood, studying the placement of his brother's prone form, then touched Mycroft's shoulder, urging him to roll onto his back. Mycroft resisted, then gave in, surrendering to the movement with a shuddering gasp. Rather than waste time, Sherlock seized the water bottle and wrenched it open, then slid his free hand under his brother's head. He levered Mycroft upright enough to tip the pills into his mouth, followed by some water, before gently guiding his brother back into a prone position.

Mycroft's hand latched onto his wrist, the tremors running through it offset by the crushing force of his grip. In the dim light from the other room and his phone, Sherlock could see that his brother's knuckles were white. Mycroft's breathing was shallow and sharp.

Sherlock waited, but Mycroft didn't seem willing to release him. Finally, he traced out a question, two symbols drawn lightly on the back of his brother's hand.

 **'#?'**

After a long moment, Mycroft tapped on his wrist.

Eight taps. Eight, presumably on a scale from one to ten. That was...troubling.

Either Mycroft's pain had not been reduced by the first dose of medication, or his pain before had been beyond agonizing.

Eight for Sherlock would have been on the order of being shot, or breaking bones. Neither experience was one he was particularly eager to repeat.

Eight sounded worse than a hangover, most of which he classed between a five and a seven.

He was still trying to formulate a course of action when the front door of his flat opened. "Sherlock? Sherlock dear? Are you all right?"

Mrs. Hudson. Sherlock identified the voice (he'd been paying too much attention to Mycroft to hear her coming), even as Mycroft made a strangled sound and released his hand to cover both ears, rolling his head into the pillows as if trying to burrow into them.

Obviously, his pain-heightened senses could not be completely protected by earplugs, nor was he even remotely capable of dealing with Mrs. Hudson's voice at the moment.

Sherlock was moving for the door even as he processed that fact, and he entirely ignored the whimsical thought that Mycroft could barely sustain contact with people under normal circumstances.

He intercepted Mrs. Hudson just as she reached the opening to his hallway. "Sherlock? What's going…?" He slapped his hand over her mouth before she could continue, took her arm in the gentlest grip he was capable of, and hustled her back out of the flat and down the stairs to her own for good measure. Once there, he released her.

"Apologies, Mrs. Hudson." He didn't normally apologize, but he thought that John would under such circumstances, and he had no wish for her to put spoiled milk in his tea because she was irritated. She'd done that once before, and the results had been unpleasant.

"Well, I like that. What was that all about?"

"As I said, apologies. I did not have a chance to warn you. Mycroft is here. Unfortunately, he collapsed in my flat. All evidence indicates he suffers from migraines, and is currently in the grip of a rather severe one. He is, at the moment, extraordinarily sensitive to both lights and noises, hence the state of my flat and my actions."

"Oh, well I suppose that's all right then." Mrs. Hudson huffed, but she also relaxed. "Although, I'd have thought you'd be playing your violin, what with the way you two get on."

"Irritating Mycroft is only entertaining when he can respond. Or when his condition is a result of his own stupidity. Neither applies in this scenario, so previous actions are not applicable. Besides, he shows signs of nausea under too much stimulus, and I don't wish to clean up after him."

"If you say so." She was smirking slightly. Sherlock decided to ignore it. "What are you going to do about him?"

"I have contacted his assistant, given him his medicine, and made him as comfortable as possible. There remain three hours and forty-eight minutes before I can determine whether a doctor needs to be called."

"Right then. You go on back up, and I'll make some food up for whenever you get peckish. Do you want some tea?"

"Not at this time. His assistant indicated that he was also sensitive to odors."

"All right then. I'll keep it down here. You go look after your brother. I'll be sure to keep it quiet, maybe settle in for a good read." She patted his arm and shooed him back up the stairs.

Back in his flat, he went to the door of his bedroom. From there, he could see that Mycroft had relaxed somewhat. Rather than disturb his brother, he went back to the living room, seated himself, and settled in for contemplation.

Mycroft's pain sat uneasily with him. Even more so when he found himself pulling out his phone and composing a text to Lestrade. The Detective Inspector had a habit of showing up unannounced, and if Mrs. Hudson was too much for Mycroft to bear, then Scotland Yard would most likely cause him to be ill. On Sherlock's bed at that.

At least, that was the reason he used to justify himself when he hit the send button.

'Indisposed for the next 24 to 48 hours. Do not attempt to contact me unless London is burning, or Moriarty walks into NSY of his own free will.'

Moments later, a low vibration signalled a reply.

'Indisposed? Sherlock...you aren't off on drugs again are you? I thought we had an agreement. I know John's wedding and all has been rough...'

He stopped reading there, typing out a rebuttal.

'The situation has nothing to do with John's wedding, or any other recent event. And I am not on drugs. If you must know, a medical matter of the purely non-narcotic or stimulant variety has arisen involving another member of my family. The unexpected advent of said matter required my involvement in said family member's care, as they were in Baker Street at the time. I assure you, my indisposition is absolutely non-voluntary.'

Another buzz. 'Right then. Suppose you tell me what happened, and I'll decide whether I ought to be making plans to raid your flat.'

Irritating, but warranted he supposed.

'Mycroft. Ill with an extreme headache that permits no external stimulus. Collapsed in my flat during our weekly meeting. And no, my brother has never been one to indulge in any form of chemical stimulation, and only moderate amounts of alcohol, none of which he consumed today.'

There was a much longer delay before Lestrade responded.

'Right. I believe you this time. But only because your language changes when you're high. And because you're a crazy bastard, but even you aren't daft enough to use your brother as an excuse when you know I can find out the truth, and get both of us on your arse.'

A few moments later, another message appeared.

'Speaking of, if I find out that I'm wrong and you ARE that daft, not only will I tell your brother, but I'll make sure every man, woman and child with a lost pet or a cat up a tree or a missing three-pence turns up at Baker Street, AND I'll blacklist you from anything interesting until you've helped at least...oh, let's say...30 of 'em. Without John and Mary's help.'

Sherlock grimaced. Lestrade had gotten both cunning and vicious over the years, and remarkably creative about providing incentive to stay out of non-sanctioned, non-case-related trouble.

Bloody pillock. Couldn't hone his talents in deduction, only in complicating his life. He almost tapped out a scathing reply, then decided it wasn't worth the effort. Besides, if he got defensive, he would make Lestrade suspicious.

He settled for something neutral.

'How fortunate then that I am, in this case, being entirely truthful.'

He smirked as he hit the send button.

Three hours later, he let himself back into his bedroom.

Mycroft had finally relaxed completely, no longer tense. He'd even shifted around to a more comfortable position on his side. Sherlock paused, then padded into the room. He bent into a crouch, then laid light fingers on Mycroft's pulse. His previous contact with Mycroft had revealed a high pulse rate, indicative of the pain he was in.

Mycroft's pulse had slowed to something closer to normal. Unfortunately, the contact woke his brother from his sleep. He stiffened. Sherlock quickly tapped on his hand, alerting him to his identity.

"Sherlock." Mycroft relaxed. His voice was soft and hoarse, barely a whisper. Still, it was an improvement.

"Mycroft." His own response was quiet, but loud enough to get past the earplugs.

"Where..."

"Baker Street. My room."

"Ah. I remember..." Mycroft trailed off with a wince.

"Number?"

"Four point six."

"Better then." Sherlock paused, then gave his brother an update in quick sentences, knowing it would prevent further agitation on Mycroft's part. "I contacted your assistant. It has been eight hours. You are in my room, wearing the sleep mask and earplugs she recommended to me. You have had two doses of your medication, and there is water beside you, in a bottle. I have contacted John, if you have need of a physician."

Mycroft sighed, sinking back and reaching tentatively for the bottle. His hand found it. "Earlier..."

"Mrs. Hudson." Mycroft's expression cleared, comprehension dawning over his drawn features.

"Of course."

"The rooms are dark, if you wish to remove the mask."

Mycroft seemed to consider it for a moment. Then one hand reached up and fumbled for the fabric. There was still a slight tremor in his arm, so Sherlock reached over and tugged it free. Mycroft blinked, his movements slow and careful. He didn't seem to be in any greater distress, so Sherlock set the mask to one side.

"Acceptable?"

"Yes." Mycroft sighed. "Eight hours?"

"Yes. Your assistant gave me instructions." He wanted to ask questions, but refrained. He didn't need Mycroft suffering a relapse. Not that it stopped them from repeating in his mind.

 _'How long has he been having migraines? Long enough to have a set routine for dealing with them. How often do they occur? Infrequent enough that I never suspected their existence. Alternative: they occur more frequently, but his control is firm enough to conceal the effects unless the pain crosses a certain threshold. That scenario is more likely. Why hide them? What triggers them? Medical research indicates different triggers for different individuals, but Mycroft would know his own triggers. He would never accept the situation otherwise.'_

He filed the questions away, formulating something else to say.

"The instructions I was provided indicate it would be unwise for you to consider moving. Your response when I brought you here supports that theory. Your assistant asked me to make you comfortable. In the interest of the quickest possible recovery, what do you need from me?"

"Only a quiet place to rest."

"I shall leave you until morning then." He turned, then paused. "Spare nightclothes, including dressing gown, are on the door. Your suit jacket and other items of apparel are on the chair, shoes underneath. I shall leave the lights off, so there should be no difficulty if you require the loo. No promises on the state of the kitchen, however, so you may want to avoid that. Phone is in your jacket pocket. I shall be nearby, if you require anything."

He left the room before he or Mycroft could say anything else. He wasn't sure which unsettled him more, Mycroft's quiet suffering, or the fact that this could be classed as the most amiable conversation they'd had in years. Or at least, the one with the least sniping that didn't involve a life or death situation.

He sent occupied himself by sending updates to John and Mycroft's assistant, informing them of his improvement. That done, he settled down to think.

He wanted to play his violin. Or work on an experiment. Or go to St. Barts. Mycroft's presence and his debilitated state made all of those impossibilities. Instead, he settled himself into his Mind Palace, pulling up his memories of Mycroft in an effort to pinpoint other times his brother had endured headaches. Perhaps he could deduce the triggers. That would be useful information.

Several hours of thought later, he emerged, frowning. He had few concrete deductions, but reviewing his observations had given him cause for concern.

 _Fact: Mycroft's offices are all inside, away from windows, with lower than normal lighting. Fact: Mycroft spends the majority of his time in said offices, or in the Diogenes Club, where silence is the rule of thumb, and lighting is, while higher, also tuned to individual preferences. He also has a room in said club that can be lit and furnished to his requirements. Fact: Mycroft prefers old movies. Black and white provides fewer bright contrasts, and older movies lack the higher volume sound effects and loud music. Fact: Mycroft's musical taste runs to classics, slower and quieter where possible. Fact: Mycroft has an ingrained, subconscious habit of rubbing his temple, particularly when he is distressed or irritated. Sometimes rubs both temples. Fact: Mycroft has specific dietary, exercise and schedule requirements. Fact: When under stress that cannot be avoided, or in environs which will provide over-stimulus, Mycroft smokes, an activity which induces relaxation and introduces chemicals which could, under the right conditions, reduce the effects of a migraine._

 _Conclusions: Could be coincidence. However, extrapolating from Mycroft's theory that the universe is rarely so lazy, and working from the hypothesis that Mycroft's behaviors are all deliberate, or at least started that way...Stress is Mycroft's most likely migraine trigger. Stress and certain deviations in diet, or nutritional imbalances. But mostly stress. Given our relationship and his job, not to mention the preparations made for the scenario of a collapse and the code word, the most logical conclusion is that Mycroft suffers frequent migraines. Perhaps daily, almost certainly weekly. Few present with the severity of this particular case, or he would never be able to conceal them. Even so, they must present with a frequency and intensity that has induced him to minimize external stimulus and aggravation as much as possible in his daily routine. Natural reticence, skills and detached personality have assisted in cultivating a persona in which all of these traits are acceptable and therefore ignored._

 _Note: Mycroft has frequently declared himself the smarter of the two of us. Possible truth may be that he is simply more affected by external stimuli. Notices more, at the cost of being more susceptible to overload. May have taken to commenting on intelligence to avoid notice of the true problem. A clever disguise, as laziness might disguise possible inabilities to cope with certain situations, such as over-exposure. Nothing proven, but worth looking into. However, if such is the case, then these episodes have been occurring for years. Possibly since adolescence._

The theory he'd formulated explained a lot about his brother. Things he'd taken for granted as simple eccentricities developed new meanings, like deductions and observations changing the clues of a case into a result different from the first one he'd postulated.

The problem lay not in his conclusion, but in what he ought to do about it. With cases, it was simple. Observe, deduce, solve, inform Lestrade, catch perpetrator.

But what should his next step with Mycroft be? He could do more observations to refine his deductions. But to what purpose? This wasn't a case to solve, and he couldn't just hand the matter off to Lestrade. There was no perpetrator to catch.

Nor was this a casual situation, where he might end with his deductions and go on his way. This required action on his part.

Well, in truth, he could ignore the situation, and he might be able to defer responsibility to John as a doctor, but...well, John and Mary would both scold him. He hated that.

No, he would have to sort out some way of dealing with Mycroft himself. Despite his own discomfort, and likely his brother's.

Feeling restless, he rose from the couch and padded to his bedroom door, peering inside.

Mycroft had changed during the interval he'd been inside his Mind Palace. His suit clothes were folded over the chair. He wore Sherlock's sweats, which Sherlock had left out for him on purpose, knowing his nicer pajamas wouldn't fit. Not when Mycroft was an inch or so taller, and slightly broader around the middle. The lower sweats were still a bit on the short side, but not horribly so, though Mycroft would probably hate it.

The same could be said of the t-shirt Sherlock had left, which Mycroft had also changed into. It was an overlarge one that he only used for sleeping, or for cases where he needed the extra space to smuggle things on his person, and it was more than large enough, even on Mycroft's wider chest and stomach.

Sherlock stood and watched his brother sleep. He'd never really had the opportunity before, though he knew Mycroft had often watched him. In sleep, much of the tension smoothed out of his brother's face. Mycroft's habitual smirks and scowls were wiped away, revealing a man who was younger than he generally appeared. It reminded him that Mycroft was only seven years his senior, barely out of his thirties. Stress and natural stoicism had aged him, adding thinning hair and lines to his face.

But then, Mycroft had always looked older than his years, even when they'd been children.

Sherlock edged closer, fascinated by this never-before-presented chance to study his brother.

Mycroft slept on his side, one hand up near his face. He would bet money that Mycroft slept with a weapon under his pillows, and a phone near at hand. Likewise, he slept facing the door, his other hand tucked over his rib-cage. He'd not bothered with blankets, his bare feet exposed to the cool evening air.

As Sherlock watched, a slight frown creased his brother's brow, his flickering eyes revealing that he dreamed. Distressing dreams, judging from his expression. He half-hoped his brother would speak in his sleep, but all that happened was a breath, a deep sigh, and then whatever images troubled him seemed to subside, as if in his sleep he had forced them away.

Given that Mycroft's ability to manipulate his Mind Palace was as great as his own, if not greater, that was not unlikely. It would be very like the elder Holmes to refuse to relinquish his control, even in unconsciousness.

Sherlock hesitated, then settled himself in the chair beside his bed. He was crumpling Mycroft's suit, but that was of little concern. Instead, he kept his attention on his brother, scooting forward to perch his elbows on his knees and bringing his palms together to put his fingers against his lips, mirroring the pose he'd often seen Mycroft in, when he'd woken in various sick-beds to find his brother sitting vigil.

The minutes ticked past, and he watched his brother. His vulnerable, wounded brother, who might wake perfectly fine, but also might wake still in pain, or in pain again.

It was so strange, sitting vigil over Mycroft. It made him feel restless. It made him feel concerned. It gave him far too much time to think, particularly about all the times he might have missed a sign that his brother was suffering. How had he not known about this?

How often had Mycroft sat like this, watching him? What thoughts had passed through his brother's mind during the long hours where he'd endured such vigils?

He remembered when Mycroft had begun rescuing him from drug dens, when he'd been in his teens and Mycroft still in university. Mycroft's silent, solemn face as he struggled through the highs, the crashes, the fallout and the detoxing.

Memories he'd long forgotten surged to the fore. Mycroft, sitting beside him as he shook and shuddered. Mycroft, wrapping blankets around him when he suffered chills. Mycroft bathing his face when he suffered fevers, or the sweating fits that left him soaked and stinking.

Mycroft, rubbing his back through the worst of his pains, when he'd been wracked with cramps and tremors, with no medicine that could alleviate them.

Mycroft, cradling his head as he vomited, keeping him from drowning in his own sick. Patiently changing him when he lost control of his body, washing him with gentle hands.

He'd long since gotten used to pushing those memories aside, closing them away in favor of memories of irritation when he recovered enough for Mycroft to lecture him, or the times when Mycroft had raided or overturned his flat to flush out all his drug supplies. It was only now, sitting in the dark, that he could admit he had been ashamed, angry to need his brother's care. He hadn't thought of that in a long time.

 _'I am not angry with you, Sherlock.'_

He'd always wondered why Mycroft insisted on saying that, especially when it seemed like a contradiction in comparison to his expressions and his behaviors.

Had Mycroft felt this, this gnawing concern? Restless thoughts in the dark, waiting to see what would happen, what consciousness would bring? This impatient itch, helpless to do anything but wait?

Had John? Was that why he'd gotten so angry over Sherlock's faked death?

He didn't like thinking things like this. He'd known for years that he was the crack in Mycroft's 'Ice-man' armor, long before Magnusson had told him, but he didn't like knowing how deep the cracks ran, and what lay behind them.

Worse, he didn't like knowing about Mycroft's pain. Mycroft's pain was likely to become a crack in _his_ armor. The indifference of a high-functioning sociopath. Having John was difficult enough. He'd nearly destroyed himself for John, to protect him and Mary. He'd only managed that by believing that Mycroft was invulnerable, and could hold things together in the aftermath.

Of course, that had been before Mycroft had confessed that losing him would break his heart. Before he had seen Mycroft's expression after shooting Magnusson and realized that the sentiment hadn't been in any form an exaggeration.

If stress was Mycroft's trigger, he shuddered to think what level headache had been produced by that particular fiasco.

Had his brother lain in a dark room, alone save for an assistant and a bottle of water, those days he was in solitary confinement? Had Mycroft been fighting a migraine on the plane, while he had been delving into his Mind Palace on the tide of the drugs in his system? Had he left the plane afterward only to collapse, as soon as he knew he was out of danger?

He didn't like thinking about things like this.

Unfortunately, he'd have to wait until Mycroft woke before he could get answers.

Time passed. Sherlock watched his brother sleep, one part of his mind going over his current cases, one part recording and categorizing Mycroft's movements in sleep. Storing information to analyze later.

Finally, two hours after dawn by his internal clock, Mycroft stirred.

It was amusing to note that his brother woke the same way he did. All at once. One minute, he slept. The next, his breathing deepened and his eyes opened. His brow furrowed, though it didn't seem to be a response to pain, because it faded a moment later. Then Mycroft spotted him. "Sherlock."

"Mycroft." He looked his brother over. "Number?"

"Less than one." Mycroft sat up, moving as easily as might be expected from a man who had spent the night curled awkwardly in an unfamiliar bed. "How long?"

"The entire night. It is two hours past dawn."

"Ah." Mycroft frowned. "Sherlock..."

"I shall return your suit, when you've answered my questions."

Mycroft sighed, but sat back. "Very well. I suppose that is not unexpected."

"How long?"

"Since secondary school. Exams in freshman year to be precise."

"How often? In general, and specifically ones of yesterday's magnitude or greater?"

"In general...fairly often. Of yesterday's magnitude or greater. Perhaps once or twice a month. I have a prescription."

"And an assistant."

"And a doctor, in the normal course of things." Mycroft's correction was mild. "A private physician, of course, who is paid for discretion and house calls."

"And the symptoms? You were nauseous yesterday, but my research indicates that headaches can be accompanied by blindness, even seizures."

"I have never been quite so unfortunate."

"Because you minimize the risks, by manipulating your environment to minimize stimulation."

"Of course." Mycroft's tone was calm. "If one cannot conquer the condition, one must work around it."

"The plane."

"Only a four. Quite manageable."

"Lazarus."

"A bit worse."

"The time directly after I was placed in solitary confinement after the events at Appledore."

Mycroft paused. Then, grudgingly, admitted "Semi-conscious for two days."

"How many times have you collapsed after seeing me through an...episode?"

Mycroft sighed. "All of them. Once you were out of danger."

"You smoke to avoid or delay them."

"Yes. It helps, at times. Not always."

Sherlock stared at his brother. There were no signs that Mycroft was deceiving him. On the contrary, he projected complete honesty.

In fact, he projected the same air he had when he was reassuring Sherlock through a bad time.

 _'I'm not angry with you, Sherlock.'_

Sherlock jerked himself to his feet. "Why did I never know?"

"I suspect you never cared to. And I had no desire to educate you." Mycroft's smile was brittle.

"Mummy and Father?"

"Aware that I am at times indisposed. They are not aware of the nature of my...condition." Mycroft stood and moved toward his discarded clothes, frowning at the wrinkles left in the fabric.

"I know now." Sherlock watched his brother strip out of overlarge sweats and shirt, then slide back into the tailored linens of his suit.

"Yes. I suppose you do."

"You shouldn't be alone. You could…."

"I manage quite well. There are...arrangements in place. And others, should I find the condition worsening."

"Sunburst."

"Precisely." Mycroft tugged his shoes on and collected his jacket. "If you'll excuse me..."

"I know now." He moved before he had time to think about it, seizing his brother's arm. "Mycroft..."

"Sherlock, really." Mycroft sighed, looking into his face. "This...unfortunate lapse...it needn't change anything between us."

"It changed you. Sitting beside me during my recovery. After...after you found me."

"Not particularly, brother mine. I have always been there for you."

That was something else Mycroft said to him, every time he fell and had to be rescued.

 _'I'm here for you, Sherlock. I will always be here for you.'_

"And if I...now that I know...if I wished to return the favor?"

"Why should you?" Mycroft raised an eyebrow.

"Why should you?" He returned the words. "It is...you are still...your loss..." He couldn't properly articulate it. "I wish to. That is all."

Mycroft studied him. For once, Sherlock let him, leaving his usual walls down. He hardly understood why he was offering to care for Mycroft the next time he was incapacitated, but he had no desire to retract his offer.

Finally, Mycroft softened. "Very well. I shall...make arrangements. But only for emergencies."

"When you fall."

"When I fall." Mycroft nodded.

Sherlock relaxed, released his brother's arm. "I...Mrs. Hudson makes excellent scones. If you're up to food."

"Perhaps one. And a cup of tea, if it's not too much trouble."

"Of course." He nodded, then opened the door and gestured his brother through it.

Forty minutes later, he saw Mycroft into one of his ubiquitous black cars, with it's heavily tinted windows. He'd received reassurances from his brother (and also from his brother's assistant on the sly) that Mycroft would only go to the office long enough to take care of a few absolutely critical matters, before he made his way home to rest.

He'd secured a further promise from 'Anthea' that she would keep an eye on his brother for the day. And that he'd receive an email at some point, detailing various treatments for Mycroft's headaches, so that he might be better prepared next time.

Not ideal, but it would do until he could prevail on his brother for further concessions. And until he could make his own observations and conclusions.

Mycroft had always been there for him, even when he had hated him for it. It was time for him to be there for Mycroft.

 _ **Author's Note:** Rewatching the series, and this insisted on being written. Some form of interaction where Mycroft is the one who needs care and attention. The migraine symptoms come from my own experience and research, so...fairly accurate, but as they say, every case is different._


End file.
